The present application relates to an apparatus and method for performing signal processing.
Switching systems are known which receive, from an external source, signals having a variety of different formats that can be routed via the switching system to specific outputs. Such switching systems, or switchers, include a control system processor, an input, a matrix card and an output. An external conversion unit, under control of a dedicated control system and control signal, is used to create a signal of a desired format which can then be supplied to an input terminal of the switcher for routing to a specific output terminal.
In some cases, a selected signal which has been received at a first input of the switcher can be output from the matrix card to an output of the switcher and then fed back to the external conversion unit for conversion. Afterwards, the converted signal can be fed to a second input of the switcher. The external conversion unit uses multiple input and output terminals of the switcher for signal conversion, and includes a dedicated control system for conversion.
Because the switcher and external conversion unit use dedicated control systems, system synchronization issues can occur. Using an input and an output of the switcher in the conversion process can increase the complexity of connections in the overall system.
For example, conversions of analog input signals to digital output signals (A/D conversion) can involve complex system connections. A conventional system for converting an analog video signal into a digital video signal includes an analog source input that accepts an analog video signal. The analog video signal is fed to an analog video router. An analog signal from the analog video router can be converted to a digital video signal and fed to a digital input source of a digital video router. The digital video router routes the digital video signal to a desired output.
Conversely, a digital signal, such as serial digital (SMPTE 259M compliant) formatted signal, from a digital video router can be digital-to-analog converted (D/A converted) and fed to an analog video router, which routes an analog video signal in a composite NTSC/PAL format to a desired output. The A/D and D/A conversions can involve a large number of cable connections and substantial coordination and synchronization.
Switching systems can consume substantial power and rack space for accommodating external conversion cards and control processors. An operator must ensure that all input and output connections are properly made, and that proper conversion connections are made. This can become more difficult when there are multiple external conversions units.